Lock



Jan. 18, 1938. E N. JACOBI 2,105,659

LOCK

Filed Nov. 6, 1936 5 Edward N Jambz Patented Jan. 18, i938 cams STATESPA ENT OFFICE LOCK Edward N. Jacobi, Milwaukee, Wis, assignor to Briggs& Stratton Corporation, Milwaukee, Wis.,'a corporation of DelawareApplication November s, 1936, Serial No. 109,417

3 Claims. (Cl. -364) This invention relates to improvements in tumblerlocks andrefers particularly to pin type tumbler locks in whichtherotatable cylinder is secured against rotation by spring pressedtumblers moving from the easing into the cylinder to be lifted toinoperative position by key operable drivers.

In the manufacture of pin type tumbler locks, great pains-have beentaken to limit the end playof the rotary cylinder to about twothousandths of an inch. If the cylinder is permitted lengthwise motionin excess of this amount, the.

resulting misalignment between the radial bores in the cylinder and inthe casing'while the key is in place would prevent the free andunobstruct inch in each of three 'or four dimensions. This to allow forsuch misalignment is not permissible as the accuracy of the lock wouldthen suiler greatly. 7

Consequently, manufacturers of pin type tumbler locks in the past haveresorted to expensive manufacturing operations, such as keeping thecasings and cylinders in matched sets after line reaming the tumblerchambers in both parts Where the cylinder and casing of the lock aredie-cast, the problem becomes particularly grave for if it would benecessary to match and ream these parts in sets, the cost of manufacturewould become prohibitive.

With these objections to past and existing pin tumbler locks in mind, itis an object of this invention to provide means whereby the entrance ofthe tumbler drivers into the casing tumblerchambersisatalitimesfreeandunobstructed even though the cylinder ispermitted a normal 'range of lengthwise shifting in the casing bore.

- With the above and other objects in view which will appear as thedescription proceeds,

this invention resides in the novel construction, combination andarrangement of parts substan 'tially as hereinafter described and moreparticularly defined by the appended claims, it being understood thatsuch changes in the precise embodiment of the hereindisclosed inventionmay be made as come within the scope of the-claims.

The accompanying drawing illustrates one complete example of thephysical embodiment of the invention constructed according to the bestmode so far devised for the practical application of the principlesthereof, and in which:

Figure 1 is a longitudinal sectional view through a pin type tumblerlock embodying this invention;

Figure 2 is a cross sectional viewthrough Fig ure 1 on the plane of theline 22; and

Figure 3 is a plan view of the lock casing per se. Referring nowparticularly to the accompanying drawing in which like numerals indicatelike parts throughout the severalviews, the numeral 5 designates thecasing of a conventional pin type tumbler lock which may be mounted in ahousing.

or other support 6 and which has a longitudinal bore 1 to receive arotatable'lock cylinder 8.

The cylinder 8 is inserted into the bore 1 from its inner end and has anenlarged flange 9 received in a counterbore ill at the inner end of thecasing. Mounted on this flange 9 is an eccentric driving lug ll throughwhich rotation of the cylinder is imparted to the mechanism controlled.

The cylinder is secured against endwise displacement in the bore by aretaining member l2 embedded in a transverse slot in the casing with itsinner edge portion projecting into an annular groove 13 in the adjacentpart of the cylinder. In this manner, the cylinder is secured againstendwise displacement, but with normal operating clearances and withoutresorting to special means to restrict the possible end play of thecylinder to a minimum, it may shift endwise as much as six thousandthsof an inch.

As is customary in the conventional pin tumbler lock, the cylinder has aplurality of radial bores or tumbler chambers 14 extending from thesurface of the cylinder into a longitudinal keyway' I 5. Slidablydisposed in these bores or chambers permitted by the drivers I6. Theouter ends 01 the tumbler chambers II are closed by a plate 2| extendinglengthwise of the casing and secured in place by swedging the metal ofthe casing over the edges of the plate, as shown in Figure 2.

As pointed out hereinbefore, under normal conditions, there is apossible misalignment between the tumbler chambers II and l I sufllcientto cause the ends of the tumbler drivers to engage the shoulders formedby the wall of the bore 1 adjacent the mouths of the tumbler chambers,and this seriously interferes with the withdrawalloi the key as thedrivers must be free to enter the tumbler drivers into the tumblerchambers ll is assured throughout the full range of possible lengthwiseshifting of the cylinder in its bore without in anywise detracting fromthe accuracy of the lock. 7 What I claim as my invention is:

1. In a tumbler lock, a bored casing, a rotatable cylinder mounted inthe bore, said casing and cylinder having radial bores adapted to bealigned,

pin type tumblers and drivers respectively in said radial bores, and theradial bores in the casing being substantially oval with their majordimension lengthwise oi the lock so as to assure free entrance of thetumbler drivers into said radial bores in the casing regardless ofnormal endwise shifting of the cylinder in the casing, while retaining aclose fit between the tumbler drivers and said radial bores in thecasing to guard against any possible rotation oi the cylinder exceptwhen the junctures of the tumblers and their drivers are in line withthe line of parting between the cylinder and easing bore.

2. In a pin tumbler look, a bored casing, a cylinder rotatable in thecasing bore, means for holding the cylinder against endwise shiftingwithin normal limits as determined by normal manufacturing practice,said casing and cylinder having radial bores adapted to be aligned, pintumblers in the radial bores of the casing, key operable drivers in theradial bores of the cylinder projectible into the radial bores of thecasing as the key is inserted and withdrawn, and said radial bores inthe casing being of oval shape with the major diameter parallel to theaxis of the lock to preclude the ends of the drivers striking the edgesof the radial bores in the casing upon misalignment of the cylinder andcasing radial bores due to normal lengthwise shifting of the cylinder inthe casing bore, while retaining a close fit between the tumbler driversand said radial bores in the casing to guard against any possiblerotation of the cylinder except when the junctures of the tumblers andtheir drivers are in line with the line of parting between the cylinderand easing bore.

3. In a pin tumbler lock having a bored casing and a lock cylinderrotatable in the casing bore, the cylinder and casing having radialbores adapted to be aligned in one position of rotation of the cylinder,spring pressed tumblers in the radial bores of the casing, key operabletumbler drivers in the radial bores of the cylinder projectible into thebores of the casing upon insertion and removal of a key, means forholding the cylinder against lengthwise displacement in the bore, saidmeans allowing normal clearance between .the parts which entailspossible lengthwise shifting of the cylinder in the bore a fewthousandths of an inch back and forth which motion is sumcient toobjectionably misalign the radial bores in the cylinder and casing, andsaid radial bores in the casing being oval-shaped with their majordiameters parallel to the axis of the lock to com-' pensate-for suchmisalignment and insure unobstructed entrance of the tumbler driversinto the radial bores of the casing during insertion and removal of thekey, while retaining a close iit between the tumbler drivers and saidradial bores in the casing to guard against any possible rotation of thecylinder except when the junctures of the tumblers and their drivers arein line with the line of parting between the cylinder-and casing bore.

EDWARD N. JACOBI.

